Cameras having interchangeable lenses of different fixed focal lengths and zoom lenses having variable focal lengths are well known. In particular for space missions, not only are particularly stringent requirements imposed on such cameras with regard to the critical operating conditions, but in addition, such cameras having a low specific weight must also be automatically operable and low-maintenance. Furthermore, such cameras should have a wide field of view with a correspondingly large focal length range of the optical system used.
One option for adjusting variable focal lengths is zoom lenses, which allow different focal lengths by the displacement of individual optical lenses and/or lens groups. Appropriate provision of adjustment mechanisms is complicated and susceptible to malfunction, in particular under the conditions prevailing in space. A quasi-continuously tunable focal length range does not outweigh the aberrations of such zoom lenses which remain after reasonable effort has been expended.
Although multiple cameras having individual fixed focal lengths provide calibrated conditions for the individual focal lengths, with high measuring accuracy and reliability, they are rather costly and installation space-consuming due to the image capture and image processing electronics systems, together with corresponding optical sensors, which must be designed separately for each camera.